Printer&#39;s plate clamping device



Se t.-l, 1936. s RQESNER 1 2,052,989

PRINTERS PLATE GLAMPING DEV ICE Filed Sept. 50, 19:55

Patented Sept. .1, 1936 A U D STATES I' NT oFFicE V 4 Claims.

inventionv relates to clamp devices for securing electrotypes and like printingplates in place on the. form.- bed of a printing press, and

has reference moreparticularly to a known type It otso-called drop-in hooks which are. employed in. connection with a honeycomb type of base o k- Honeycomb base blocks of the type above mentioned are formed with rows' of closely spaced holes. of uniformdiameter, each of the holes being undercut at or near its lower endtto provide. an; annular shoulder. One known type of drop-in. hook employs a pair of members pivotally connected at. their lower ends thatare i'ns'eritable from'above in the hole, one of the members having on its upper end a. lip or jaw to engage with the edge of an electrotype plate or thelike, and a screwmounted in athreaded hole in. its. upper. end portion and jaw, and the 29 other member havingv an. inclined surface onits upper end that is engagedby the tip. of the screw as the latter is forced downwardly by a. key iav'rer cliv sojas. to spread. theupper portions of thejm'e'm'bers'. andforce. the lip or jaw into clampmg engagement with theplate, said. other mem: her also havingnorr its lower end a lateral toe that through engagement withthe shoulder on the'wall'of the hole, prevents arising movement of the device during the locking operation.

Myspresent invention relates to the abovena'med' type of drop-in hook and is based on the broad mechanical principle thereof; but has for its object to provide a simpler, less expensive, and more efficient device than has hitherto been known, the reduction in the cost of manufacture being due mainly to the fact that the principal body member of the device can be made on a punch press by a single stamping operation. Enormous quantities of plate clamps are required in any large printing establishment, so

that the item of cost is a very material factor.

An approved and preferred form of my invention is illustrated in the accompanying drawing, in which- Fig. 1 is a vertical section through a fragment of a base block and electrotype plate thereon showing my improved clamp, also in section, applied thereto; the drawing showing the device 50 about twice life size.

Fig. 2 is a top plan view of Fig. 1. Fig. 3 is a fragment view similar to Fig. 2 but showing the device in collapsed position.

Fig. 4 is a longitudinal vertical section through 55 the body member.

Fig. 5 is a similar section through the expander arm;

Fig. 6 is a side elevation of the device as viewed from the left of Fig. 3.

Fig. 7 is an opposite side elevation as viewed '5 from theright of Fig. 3. I p

In the drawing, I0 designates as an entirety a fragment of the honeycomb base block, and I I- designates the narrow undercut annular shoulder'f'ormed in each hole of theblock. I2 desig- 1'0 nates an electroplate having the 'usual beveled edge I3 that is mounted on the base Ill.

The drop-in hook ordamp comprises only four parts, consisting of a body member I4; an V expander arm I5, 2,. hingepin. IBby which the 1'0 lower ends of the. members I4 and I5 are pivotally united, and ascrew I'I. The body member I 4 is. of substantially"semi-cylindrical form in cross section; as shown by; Fig. 2, and integral with its upper end is a. transversely extending 0 lip. or. jaw I8, the outer face of which has a bevel corresponding to. the bevel I3 of the plate I2. At the base ofthe plate-engaging sideqof the jaw I8 is a transverse groove I9. About midway of the body member M the material is out 25 and punched rearwardly to-forman integral internal' cam 20, and on the lower. end of the body member, below' the cam 20, is a. narro w hook 2|. The opposite sidewalls of the-body member. I l at r their; lower end. are. formed, with-.;l 1o1 es 22 30 for engagement with the hinge pin I6.

The expander arm I7 is formed in its upper end with an internally threaded hole 23 and, directly below the hole, with a longitudinal groove or recess 24, the purpose of which is two-fold- 35 to provide space for the downward travel of the screw, and also space to receive the projecting cam 20 when the two members I4 and II are collapsed as shown in Figs. 3 and 7. The lower end of the arm I? fits between the opposed sides 4 of the body member I4 and has a hole 25 that registers with the holes 22 of the body member, the registering holes receiving the hinge pin I6. Engaged with the threaded hole 23 is the screw 21 formed with a smooth rounded lower end or 45 tip 28 that is adapted for sliding engagement with the cam 20. In the upper end of the screw is a polygonal socket 29 that receives the ordinary key wrench 30 such as is employed for locking clamps of this type in the base block.

When using the device, the screw 21 is first backed out to the point where its tip is substantially flush with the lower end of the threaded hole 28. In this collapsed position of the parts the expander arm I! is nested in the body memher M, as shown in Fig. 3. The device is then, either by the thumb and finger or by a special tool sometimes used, dropped into the hole and adjusted sidewise until its lip or jaw I8 overlaps the beveled edge of the plate l2. The key wrench is then applied to the screw and the latter is screwed downwardly, the sliding contact of its tip with the cam 20 expanding or spreading the upper portions of the members l4 and I1 until the upper end of the arm I! strikes the opposite side of the wall of thehole, as shown in Fig. 1.' At the same time, this thrust engagement of the screw with the cam forces the hook 2| of the body f member beneath the shoulder ll of the hole, as

shown in Fig. 1, so that the device is securely locked from accidentally falling out of the hole.

The groove or kerf l9 at the base of the jaw l8 permits the jaw to grip the'plate even though the lower edge of the latter may slightly overlap the maybe made from sheet metal by a single: opera tion in a punch press having a suitably shaped die therefor, while the cooperating expander arm ll can also be made from round stock by a few simple machine operations. This makes the device very inexpensive to manufacture, without any sacrifice of efficiency.

I claim 1'. A printer's expansible drop-in hook adapted for use in the holes of a honeycomb base block, comprising a body member formed with a plateengaging jaw on its upper end, a cam on its intermediate portion on the opposite side from said jaw, and a hook on its lower end on the same side as said jaw, and an expander, comprising an arm pivoted at its lower end to the lower end of said bodymeinb'er', and a screw in its upper end adapted to be; screwed downwardly in sliding contact with said cam to thereby spread the'upper portions of said body member and arm and force said hook beneath a' shoulder on the wall of the hole. 2. A'p1inters'expansib1e drop-in hook adapted for use in the holes of a honeycomb base block, comprising a body member of substantially semicylindrical form in cross section having a plateengaging jaw on its upper end, an internal cam on its intermediate portion on the opposite side from said jaw, and a hook on its lower end on the same side as said jaw, and an expander, comprising an arm pivoted at its lower end in the lower end of said body member, said arm shaped to substantially nest within said body member when the two are collapsed, and a screw in the upper end of said arm adapted to be screwed downwardly in sliding contact with said cam to thereby spread the upper portions of said body member and. arm and force said hook beneath a shoulder on the wall of the hole.

7 3. A printers expansible drop-in hook adapted for use in the holes of a honeycomb base block, comprising a body member formed with a plateengaging jaw on its upper end, an integral internal indented cam substantially mid-length thereof and on the opposite side from said jaw, and an integral hook on its lower end on the same side as said jaw, and an expander, com

prising an arm pivoted at its lower-end to the lowcylindrical form in cross section having a plateengaging jaw on its upper end, a transverse groove at the base of the plate-engaging side of said jaw, an internal cam on its intermediate portion on the opposite side from said jaw, anda hook on its lower end on the same side as said jaw, and an expander, comprisingan arm pivoted at its lower end inthe lower end of said body member, said arm shaped to substantially'nest SIEGMUND ROESNER. 

